Variable height pile cutting means for double pile fabric looms and the method therefor



Oct. 22, 1968 c. H. HASTEWELL ET AL 3,406,725

VARIABLE HEIGHT FILE CUTTING VEANS FOR DOUBLE FILE FABRIC LOOMS AND THE METHOD THEREFOR Filed Jan. 17, 1967 4 Sheets-Sheet 1 IN ME N TOPS (ml/0E HUBER? #45275 WELL ZEO/WiRD HAROCHS TLE Oct. 22, 1968 c. H HASTEWELL ET 3,406,725

VARIABLE HEIL'HT FILE CUTTING MEANS FOR DOUBLE FILE FABRIC LOOMS AND THE METHOD THEREFOR Filed Jan. 17, 1967 4 Sheets-Sheet 2 IN VE N TOPS CLAUDE HUB/5K7 H4575 WELL LEON/4RD Hneocnsns ATTORNEYS Oct. 22, 1968 c HASTEWELL ET AL 3,406,725

VARIABLE HEIGHT FILE CUTTING MEANS FOR DOUBLE PILE FABRIC LOOMS AND THE METHOD THEREFOR Filed Jan. 17, 1967 4. Sheets-Sheet 5 IN VE N TORS CLAUDE HUBEFT H457WELL LEM/2R0 flame/45715 'HTTOBNE'YS Oct. 22, 1968 H HASTEWELL ET AL 3,406,725

VARIABLE HEIGHT FILE CUTTING MEANS FOR DOUBLE FILE FABRIC LOOMS AND THE METHOD THEREFOR 4 Sheets-Sheet 4.

Filed Jan. 17, 1967 l N VE' N TOIQ-S C Al/0E Hug er Hnsre WELL BYLEO/VHRD 1 /420005 TLE 152w a/%;/M/

ATTORNEYS United States Patent 3,406,725 VARIABLE HEIGHT PILE CUTTING MEANS FOR DOUBLE PILE FABRIC LOOMS AND THE METH- OD THEREFOR Claude Hubert Hastewell and Leonard Hardcastle, Scissett, near Huddersfield, England, assignors to G. H. Norton & Company Limited, Yorkshire, England, a British company Filed Jan. 17, 1967, Ser. No. 609,867 Claims priority, application Great Britain, Jan. 18, 1966, 2,371/66 17 Claims. (Cl. 139-21) ABSTRACT OF THE DISCLOSURE In a double pile fabric loom in which a face-to-face weaving process is performed a knife reciprocating between the two interconnected woven fabrics to cut the pile yarn, provision is made for producing woven fabrics having varying pile heights by repetitively adjusting the position of the plane of movement of the knife relative to the planes of the two face-to-face fabrics as weaving proceeds.

This invention relates to woven pile fabrics or materials and is particularly concerned with looms for the manufacture of woven pile fabrics or materials such as, for example, imitation fur fabrics, carpets, rugs and the like.

In the manufacture of woven pile fabrics or materials it is often desired to provide a pile of different heights. In this way sculptured and/or decorative effects may be obtained as well as an imitation of the long or guard hairs and short or ground hairs of natural for in the production of imitation fur fabrics, and numerous efforts have been made to produce imitation fur fabric having this distinctive characteristic. Thus it is known to weave imitation fur fabric with a pile of constant height but using yarns or filaments having different shrinkage characteristics and thereafter treating the fabric in a special shrinking process to produce an imitation fur having a pile of different heights. Such processes are, however, costly and inconvenient to operate as the application of the various different yarns or filaments in the weaving process is complicated, their degree of shrinkage is variable and difficult to control, and moreover the available choice of yarns or filaments having the necessary shrinkage characteristics and which are also suitable for use together in such a process is not large.

In the known face-to-face weaving process two pile fabrics or materials are woven face-toface with at least one common pile-forming yarn or filament interconnecting the parallel ground yarns or filaments of said fabrics or materials, cutting means being provided which travels between the face-to-face fabrics or materials to cut the pile yarn or filament and thus produce two face-to-face pile fabrics or materials. The present invention is based on the concept of achieving the desired effect in such a process by making the positive of the travelling cutting means automatically variable relative to the ground yarns or filaments of said fabrics or materials in predetermined manner as weaving proceeds so as to bring about a predetermined variation in the height of the cut pile of the two face-to-face pile fabrics or materials produced.

Thus viewed from one aspect the invention provides, in a weaving loom for carrying out the face-to-face Weaving process as defined above and including cutting means movable between the two woven fabrics or materials transversely of the direction of weaving to cut the pile yarn or filament, adjusting means for automatically im- 3,406,725 Patented Oct. 22, 1968 ice posing on the transverse cutting motion of the cutting means as weaving proceeds a predetermined variation of the position of the cutting means relative to the ground yarns or filaments so as, in operation, to bring about a predetermined variation in the height of the cut pile of the two face-to-face pile fabrics or materials thus produced.

The cutting means will, as is often the case in known face-to-face weaving looms, preferably be arranged to cut a single transverse row of the pile yarn or filaments at each of its movements-across and between the woven fabrics or materials, i.e. on each of its strokes, and it will be understood that the height of the pile produced on one of the said fabrics or materials will differ from the height of the pile on the other fabric or material unless, of course, the cutting point of the cutting means lies exactly midway between the two ground yarns or filaments.

As well as being varied from stroke to stroke the position of the cutting means relative to the ground yarns or filaments may if desired be varied during its stroke so as to produce differing pile heights in individual transverse pile rows. Clearly to produce a predetermined overall sculptured effect suitable programming means such as electronic or mechanical means will be provided to control the variations in position of the cutting means. More simply and in particular to produce an imitation for fabric it may be sufficient to alter the position of the cutting means between strokes thereof so that the pile heights of the two face-to-face fabrics or materials produced at each stroke are constant and vary merely from row to row.

It will be understood that the cutting means will have two or more positions relative to the ground yarns or filaments between which it is repetitively movable in operation to provide a corresponding number of different pile heights in each of the face-to-face fabrics or materials. For the sake of simplicity of operation, but by no means necessarily, such positions may be symmetrically spaced to one side and the other of an imaginary plane of reference lying between and parallel to the planes of the ground yarns or filaments in operation. Obviously, however, there are very many different ways in which apparatus may be set up and operated in accordance with the invention to produce cut piles whose heights vary in all manner of patterns.

In a simple and preferred form of the invention the cutting means has only two positions relative to the ground yarns or filaments of the fabrics or materials which are situated equidistantly one on each side of a plane midway between the planes of the two ground yarns or filaments in operation and the cutting means is arranged to alternate between such two positions. Alternate rows of pile in each of the face-to-face fabrics or materials will therefore be of mutually equal height and the pile rows in each piece of fabric or material will be in turn long and short. Moreover the long pile rows in each respective piece will be of the same height as one another, as will the short pile rows.

Various ways of putting the invention into effect in known looms are envisaged. The cutting means in a faceto-face loom usually comprises a knife mounted on a carriage movable along a knife race. In some looms it is possible to adapt the mounting of the race to vary the position of the knife race eg by mounting it for rectilinear or pivotal movement transverse to the plane of weaving, i.e. up and down where the knife race extends horizontally and weaving takes place in a horizontal plane, so as to enable the position of the knife to be varied in the desired manner. Alternatively, Where the position of the knife race cannot be altered, the knife itself may be mounted for movement, e.g. rectilinear or pivotal movement, relative to the race to enable the positioftbftlfe knife "fo 'be vafieci andllitis altef the pile height. In the latter case two or more knives may be mounted on the carriage each being movable between operable and inoperable positions and in the operable position performingits cutting action, the different knives producing cut piles of different heig'htsythus such knives may be'retractable and extendible in the carriage, suitable control means being provided for extending and retracting such knives in a predetermined sequence to render selected ones operable as desired. It will be understood that the latter arrangement will not necessitate any provision for variation of the position of the knife race or the path of movement of the knife carriage.

Where means are provided for adjusting the position of the knife of knives mounted on the knife carriage, such means may take the form of stationary control elements engageable with the knife or its mounting at the end of each stroke thereof to bring about such adjustment either mechanically or electrically, e.g. by some kind of overdead-centre spring control means associated with the knife or by electrically operated solenoid means.

Direct or indirect movement of the knife or knives referred to above may be effected in any suitable manner, e.g. mechanically, electrically, pneumatically or hydraulically, generally depending upon what is most convenient having regard to the particular type of loom to which the invention is to be applied. In a preferred construction in which the knife race is mounted for transverse rectilinear vertical movement such movement is effected by hydraulic jack means acting on the race, e.g. in the form of a pair of hydraulic slave cylinders arranged one at each end of the race and controlled by a master cylinder.

The primary control for instigating each variation of the position of the cutting means and thus synchronising such variation with the weaving operation of the loom may in suitable cases be taken from some readily accessible part of the loom itself which performs movement related to each successive step in the forward motion of the woven product in operation, i.e. related to the formation of each successive row of the pile. Alternatively or where changes in the positioniof the cutting means during a stroke are required such control may be effected by programming means not forming an essential part of the loom but whose operation is synchronised therewith.

Where, as in a preferred form of the invention referred to above, the said adjusting means is arranged repetitively to vary the position of the knife race to adjust the position of a single knife by hydraulic jack means acting on the knife race, the operation of such jack means may conveniently be controlled by rotary cam means driven by the loom mechanism.

In a preferred arrangement operation of the hydraulic jack means to effect lifting and lowering of the knife race is effected by a first rotary cam, a mechanical linkage being provided between the said first rotary cam and the said hydraulic jack means, and means for rendering such linkage alternately operative and inoperative so as to control the frequency of lifting and lowering of the said knife race. The said means acting on the said linkage may then be controlled by a second rotary cam.

In a preferred embodiment the above mentioned linkage includes a lever adapted to be rotated above a first axis by the said first rotary cam to operate the said master cylinder to lift the knife race, releasable locking means arranged automatically to maintain such lever in its master cylinder operating position when it is moved thereto by said first rotary cam, said second rotary cam being arranged repetitively to release said locking means and to cause said lever to be rotatable about a second axis whereby the knife race is lowered and operation of the master cylinder by said lever is temporarily prevented.

In one convenient arrangement the said first rotary cam is driven in rotation by the low shaft of the loom,

4 whilst thesaid second rotary cam is driven by the shedding tappet box shaft.

It will be understood that a loom embodying the invention may easily be set to produce any desired pattern ofpile heights by suitable choice of the configuration ofthe rotary cams referred to above and/or of their rate of rotation, which latter feature of the cam operation may be adjusted by suitable choice of gearing through which the cams are-driven or by mounting the cams on different rotary parts of the loom which rotate at varying rates relative to the forward movement of the woven product in operation. I

The apparatus may also include means whereby the positions to which the cutting means is repetitively adjusted in operation may be varied without difliculty so as to set up the apparatus to produce various desired pile heights. In thepreferred embodiment referred to above such a facility may be provided by the provision of appropriate meansfor varying the working strokes of the said hydraulic cylinders.

- It will be understood that the invention is by no means limited to the provision of means for adjusting the position of the cutting means after every successive cutting stroke thereof or, indeed, in a manner to cut each pile row in a different position from the previous one. Clearly the position of the cutting means may be so controlled as to effect the cutting of a number of successive pile rows in the same position if desired, followed by adjustment of the cutting means to a new position; it will, in fact, be understood that the apparatus may be set to operate automatically in very many different ways depending upon the desired characteristics of the pile in the finished prodnot.

The invention also extends to a method of producing a woven pile fabric or material having a pile of different heights, by operating the face-to-face weaving process as hereinbefore defined in a weaving loom including cutting means movable between the two woven fabrics or materials transversely of the direction of weaving to cut the pile yarn or filament, such method comprising automatically imposing on the transverse cutting motion of the cutting means as weaving proceeds a predetermined variation of the position of the cutting means relative to the ground yarns or filaments so as, in operation, to bring about a predetermined variation in the height of the cut pile of the two face-to-face pile fabrics or materials thus produced. The invention further extends to a woven pile fabric or material having a pile of different heights, when produced by the method set forth above.

In order that the invention may be more readily understood, the relevant features of one embodiment of a loom embodying the same will now be described by way of example and with reference to the accompanying drawings, in which:

FIGURE 1 is a view in elevation, looking from the downstream end of the loom, of the knife race and its supports, with the central part of the race removed;

FIGURE 2 is a diagrammatic side elevation of the loom, looking from the left-hand side thereof relative to the FIG. 1 illustration;

FIGURE 3 is an enlarged side elevation of part of the loom as seen in FIG. 2, showing the elements of the knife race adjusting mechanism in a first condition of adjustment;

FIGURE 4 is a View similar to FIG. 3 but showing such mechanism in a second condition of adjustment; and

FIGURE 5 is a diagrammatic cross-sectional view illustrating the manner in which the two woven pile products are separated by the cutting means.

In this embodiment the invention is applied to a faceto-face weaving loom of a kind in which the normally fixedly mounted knife race may conveniently be adapted for vertical reciprocating movement. The invention is applied in its simplest form, to vary the position of the single knife relative to the ground yarns or filaments of the woven fabrics or materials between an upper and a lower level spaced equidistantly above and below a plane midway between and parallel to the planes of the upper and lower ground yarns or filaments.

Thus, referring first to FIG. 5, the effect of the apparatus of the invention is to cause a knife race 1 carrying a knife carriage 2 mounting a knife blade 4 to be reciprocated vertically between a lower position shown in full lines and an upper position shown in dashed lines. A cutting stroke of the knife with the race in its lower position will clearly produce a transverse pile row 50 having a short pile in the lower fabric or material 51, whose ground yarn or filament is indicated at 52, and a transverse pile row 53 having a long pile in the upper fabric or material 54 whose ground yarn or filament is indicated at 55. Subsequent movement of the race to its upper position will clearly have the opposite effect, so that a predeterminable series of rows of long and short pile will be produced in each piece of fabric or material.

Referring now to FIG. 1, the knife race 1 has the knife carriage 2 reciprocable back and forth along it by means of an endless rope which runs over a reciprocating drive pulley 3 at each end of the race; each run of the knife carriage 2 in each direction constitutes a pile cutting stroke. Upper and lower honing stones (not shown) between which the knife blade 4 (FIGS. 2 to 5) passes during each stroke are, as usual, provided in association with the knife race and are secured to the same to move up and down with it.

The knife race is mounted adjacent each of its ends on a vertical pillar 5 carrying a horizontal cross-bar 6 at its top secured to the underside of the race 1, such pillars 5 being vertically slidable in fixed sleeves 7 mounted on two of the main frame members 8 of the loom.

Also fixedly mounted on the frame members 8 of the loom are a pair of hydraulic slave cylinders 9, one at each end of the knife race 1 and underlying the same so that their piston rods are operable to raise and lower the race through a distance equal to the desired spacing between the intended upper andlower positions of the knife. Compression springs 10 bias the slave cylinder-s to their rest conditions and act to prevent the knife race bouncing; a heavy tension spring 11 connected between the race and a fixed part of the loom frame also biases the race downwardly. The said slave cylinders 9 are controlled by a master cylinder 12 which is actuated in a manner now to be described with reference to FIGS. 2 to 4.

The master cylinder 12 is provided with an operating rod 13 inward movement of which, i.e. as indicated by the arrow A in FIG. 3, operates the master cylinder and the slave cylinders 9 to lift the knife race to its upper position shown in dashed lines in FIGS. 1 and 3.

Such inward operative movement of the rod 13 is brought about by way of a main operating lever 14. In one condition of the mechanism (see FIGS. 2 and 3) the lower end of the lever 14, which carries a trunnion 15 entrapped in a slideway 16, is secured for pivotal movement of the lever about the axis of its trunnion, the trunnion being held at the right-hand end of the slideway 16 by a pivotally mounted locking dog 17. Pivotal movement of the lever 14 clockwise as seen in FIG. 3 will clearly move the rod 13 to the right to operate the master cylinder 12.

Such movement of the lever 14 is brought about by the action of a first rotary cam 18 on a cam follower roller 19 mounted on the lever, the lever being biassed against such cam by a tension spring 20 acting on its lower extremity. The cam 18 is keyed on the low shaft 21 of the loom.

As seen in full lines in FIG. 3 the lever 14 is in the process of its movement to the right to operate the master cylinder. When it reaches the full extent of such movement, shown in dashed lines in FIG. 3, the lever is automatically locked in its operative position by a locking arm 22 freely pivotally mounted on a fixed upright 23, which locking arm is slidable in a slot formed in the upper end of the lever and drops into its position shown in dashed lines to lock the lever in its said operative position. It will thus be seen that, once the lever 14 has been moved to its operative position by rotation of the cam 18 to the position shown in dashed lines in FIG. 3 it will be held in such position even when the cam 18, in its continued.

rotation, disengages from the cam follower roller 19. The knife race will thus be held in its upper position for the time being.

Further mechanism is provided for periodically releasing the lever 14 for return movement to the left as seen in FIGS. 3 and 4 under the influence of the spring 20, so as to cause the knife race to be lowered.

Such mechanism comprises a release shaft 24 mounted on one end of a double-armed lever 25 biased in the anticlockwise sense by a tension spring 26 secured to the loom frame. The release shaft 24 has two compression springs 27 and 28 mounted thereon, the spring 27 engaging under the locking dog 17 and the spring 28 under the locking arm 22. It will thus be seen that upward movement of the release shaft 24 will cause the dog 17 to be lifted to free the trunnion 15 at the lower end of the lever 14 for movement along the slideway 16, and the arm 22 also to be lifted to free the upper end of the lever 14 for movement to the left. FIG. 4 shows the dog 17 and the arm 22 in their raised positions.

Rotation of the double-armed lever 25 to raise and lower the release shaft 24 is controlled by a second rotary cam 29. Such cam is driven in rotation via reduction gears 30 and 31 from the shedding tappet box shaft 32 of the loom; the shedding tappet box of the loom, which is generally indicated at 33 in FIG. 2, is a conventional part of the loom mechanism by which the structure of the woven fabric or material is determined. The cam 29 actuates a rocker arm 34 via a cam follower roller 35, the rocker arm being linked to the left hand end of the doublearmed lever 25 and thereby biased downwardly by the action of the spring 26 so as to maintain the roller 35 in engagement with the cam 29.

When the cam 29 is in the position shown in FIG. 3 the rocker arm 34 is raised and the release shaft 24 is thereby held in its lower position against the influence of the spring 26. When the cam 29 rotates to the position shown in FIG. 4, however, the spring 26 is able to rotate the lever 25 to raise the shaft 24 to the position shown in that figure, with the result that the locking dog 17 and locking arm 22 are raised to release both the lower and upper ends of the main operating lever 14 as aforesaid.

The effect of such release of the lower end of the lever 14 is that it is no longer constrained to rotate about the axis of its trunnion 15 as the latter is now free to slide in the slideway 16. As a result the action of the cam 18 on the lever 14 is now effective to swing it back and forth about an axis adjacent the outer end of the operating rod 13 of the master cylinder, as indicated by the arrow in FIG. 4; such movement of the lever 14 has no effect on the master cylinder and the knife race thus remains in its lower position to which it was moved when the lever 14 moved to the left upon its release from the restraint of the locking arm 22.

Further rotation of the cam 29 towards a position thereof equivalent to that of FIG. 3 causes the release shaft 24 to be drawn downwardly once again with the result that the locking dog 17 again engages over the trunnion 15 of the main operating lever to secure the trunnion at the right hand end of the slideway 16, so that the lever 14 will once again be constrained to rotate about the trunnion axis and will be acted upon by the cam 18 to operate the master cylinder and thereby raise the knife race to its upper position.

It will thus be seen that the knife race will be continuously raised and lowered as weaving proceeds. The frequency with which the race is raised and lowered relative to the rate of production of transverse pile rows in the loom will, of course, depend on the rate of rotation and the particular synchronization of the two cams 18 and 29, and will be set in dependence on the effect which it is desired to produce in the finished fabric or material. Thus the mechanism could if desired be set to produce alternate long and short pile rows in each of the finished fabrics or materials, by causing the knife race to be raised or lowered between each pick of the loom, i.e. at the same rate as the rate of production of transverse pile rows. Alternatively the knife race may be caused to be held in its raised and/or lowered position each time for more than one pick of the loom whereby a corresponding number of transverse pile rows will be cut without the knife race altering its position. It is not, of course, an essential feature of the apparatus that the knife race should be held in its upper position for the same number of picks of the loom as it is held in its lower position during each cycle; in'this way the numerical relationship of long and short pile rows may be made to ditfer in the two woven fabrics or materials which are produced.

The rate of rotation of -the cams 18 and 29 may be adjusted by suitable choice of driving gears therefor; the cam 18 may of course be driven through gears if desired, as is the cam 29. Also different rates of rotation of such cam may be achieved by driving them from parts of the loom mechanism other than the low shaft and the shedding tappet box shaft respectively; the latter members are thus only two examples of parts of the loom mechanism from which rotation may be imparted to the cams.

It'will thus be seen that the invention is applicable in a simple robust and versatile manner to known looms. Moreover this invention removes a necessity for reliance to be placed on special methods to control shrinkage or for any other special finishing processes specifically for the purpose of bringing about a contrast in pile length. It neither requires nor precludes the use of yarns or filaments with specific shrinkage characteristics which may otherwise be suitable and any normal shrinkage which may take place during the normal finishing processes appropriate to pile fabrics is in no way detrimental to fabrics produced by this method.

We claim:

1. In a loom weaving face-to-face pile fabrics having ground material and pile material and including cutting means movable between the two woven fabrics transversely of the direction of weaving to cut the pile material, adjusting means for automatically imposing on the transverse cutting motion of the cutting means as weaving proceeds a predetermined variation of the position of the cutting means relative to the ground material so as, in operation, to bring about a predetermined variation in the height of the cut pile material of the two faceto-face pile fabrics produced.

2. Apparatus as claimed in claim 1 including means for actuating said adjusting means between transverse cutting movement of said cutting means; said cutting means cutting a single transverse row of pile material during each cutting movement.

3. Apparatus as claimed in claim 2 wherein said means for actuating said adjusting means comprises loom mechanism operable in synchronism with the weaving of successive pile rows.

4. Apparatus as claimed in claim 1 wherein said cutting means is adjustable to two positions relative to said ground materials, said positions being symmetrically spaced on opposite sides of an imaginary plane between and parallel to the planes of said ground materials.

5. Apparatus as claimed in claim 4 wherein said imaginary plane is midway between the planes of said ground materials and wherein said adjusting means operates to adjust said cutting means between said two positions alternately.

6. Apparatus as claimed in claim l-wherein said cutting means comprises a knife movable along a transverse knife race, said adjusting means being operable to change the position of said knife race.

7. Apparatus as claimed in claim 6 wherein the planes of said ground materials are horizontal and wherein said race is adjustably movablevertically.

8. Apparatus as claimed in claim 7 wherein said adjusting means comprises hydraulic motor means drivingly connected to said knife race.

'9. Apparatus as claimed in claim 8 wherein said hydraulic motor means comprises a slave motor at each end ofsaid knife race and a master cylinder device for controlling both said motor means.

10. Apparatus as claimed in claim 9 including rotary cam means driven by said loom for controlling the operation of said master cylinder device.

11. Apparatus as claimed in claim 10 wherein said rotary cam means comprises a first rotary cam for effecting operation of said motor means to lift and lower said knife race; a mechanical linkage drivingly connecting said first rotary cam to said master cylinder device; and

means for rendering said linkage alternately operative and inoperative to thereby control the frequency of lifting and lowering said knife race.

12. Apparatus as claimed in claim 11 wherein said loom includes a low shaft, said first rotary cam being driven in rotation by said low shaft.

13. Apparatus as claimed in claim 11 including a second rotary cam comprising said means for rendering said linkage operative and inoperative.

14. Apparatus as claimed in claim 13 wherein said loom includes a rotary tappet box shaft, said second cam being driven in rotation by said tappet box shaft.

15. Apparatus as claimed in claim 13, wherein the said mechanical linkage includes a lever pivotally mounted for rotation about a first axis by the said first rotary cam to operate the said master cylinder device to lift the knife race, and releasable locking means arranged to automatically maintain said lever in its master cylinder operating position when it is moved thereto by said first rotary cam, said second rotary cam being arranged to repetitively release said locking means and to cause said lever to be moved away from said master cylinder device whereby the knife race is lowered and operation of said master cylinder device by said lever is temporarily prevented.

16. A method of producing a woven pile fabric having a pile of different heights, by performing a face-to-face weaving process to produce face-to-face pile fabrics having ground material and pile material, such process being carried out in a loom including cutting means movable between the two woven fabrics transversely of the direction of weaving to cut the pile material, such method comprising automatically imposing on the transverse cutting motion of the cutting means, as weaving proceeds, a predetermined variation of the position of the cutting means relative to the ground materials so as to bring about a predetermined variation in theheight 0f the cut pile of the two face-to-face pile fabrics produced.

17. The woven pile fabric produced by the method defined in claim 16.

References Cited UNITED STATES PATENTS v 1,520,274 12/1924 Benoit 139-29l 3,187,779 6/1965 Smiley et al. 1397 HENRY S. JAUDON, Primary Examiner. 

